1. Field of the Invention
The present invention relates to an information processing apparatus having a power saving mode, a control method therefore, and a storage medium storing a program for executing the control method.
2. Description of the Related Art
To reduce power consumption of an information processing apparatus operable either in a normal mode or in a power saving mode, a shift to the normal mode is made, e.g., in response to a job being input, and a shift to the power saving mode is made, e.g., in response to the job having been processed.
However, a shift from the power saving mode to the normal mode requires large electric power and takes a long time. Therefore, with the information processing apparatus designed to always enter the power saving mode in response to a job having been processed, power consumption cannot effectively be reduced and the information processing apparatus does not promptly become operable as needed.
To eliminate these problems, an image forming apparatus disclosed in Japanese Laid-open Patent Publication No. 07-251550 is configured to measure a job interval (i.e., a time period from when a preceding job is executed to when a current job is executed), set a waiting time, after which the power saving mode is entered, based on the measured job interval when the current job is completed, and cause the information processing apparatus to enter the power saving mode when the set waiting time has elapsed after completion of the job. Specifically, if the job interval is long, it is determined that the frequency of use of the information processing apparatus is low and therefore the waiting time after which the information processing apparatus enters the power saving mode is set to be short. On the other hand, if the job interval is short, it is determined that the frequency of use of the information processing apparatus is high and the waiting time is set to be long.
However, even if the job interval is long, the frequency of use of the information processing apparatus is not always low. It is sometimes preferable that the waiting time after which the information processing apparatus enters the power saving mode is set to be long when any of the following conditions is met, even if the job interval is long. For example, in a case that a job input instruction, e.g., for copying, is given by a user by operating an operation unit of the information processing apparatus, and in a case that an instruction to input a job of a type which is high in occurrence frequency is given by a user via the operation unit, there is a high possibility that the next job is input immediately thereafter. In another case that an input job is a form print job or other job for continuously inputting data, there is a high possibility that data are successively input thereafter. In still another case that no job has been input for a long period of time such as at the first thing in the morning or at the first day after long holidays, there is a high possibility that a job is input immediately after the power is turned on. In still another case that a print job is input via the network and a job average execution time is equal to or longer than a predetermined time as in, e.g., the printing of a large number of pages, the next job is input after inspection of printing result and therefore there is a high possibility that the next job is input immediately.
On the other hand, even if the job interval is short, it is not inevitably necessary for the information processing apparatus to be in a standby state for a predetermined time period before being shifted to the power saving mode. More specifically, even if the job interval is short, it is sometimes preferable that a time period after which the information processing apparatus is shifted to the power saving mode is set to be short when any of the following predetermined conditions is met. For example, in a case where a setting is made not to use the printer (e.g., a setting is made to perform a degeneracy operation in which the printer is not used when the printer is in an abnormal state, or a setting is made such that a FAX transmission result report or FAX reception data is not printed, but stored in a memory or in an HDD), an immediate shift to the power saving mode can be allowed since a job can be executed immediately after restoration from the power saving mode. In another case that a frequently used host is not in operation and hosts which are less in number than a predetermined number are in operation, an immediate shift to the power saving mode can be allowed since it can be determined that the power supply to the information processing apparatus will soon be turned off.